There have been a number of major developments, in the design of back packs, which are of interest with respect to the present invention. One such development has involved the incorporation of a frame with the pack bag and the connection of this frame to a hip belt, whereby part of the load may be transferred to the hips of the user. In addition, internal frames, comprising stays sewn into pockets of the bag, have, to some extent, supplanted the earlier rigid rectangular frames. Such internal frames, often consisting of spaced, vertical stays, permit one side of the frame to move relative to the other, as the user moves beneath the load. To achieve a further degree of flexibility, special connections between the frame and the belt have been developed, to permit of some freedom of relative movement between the belt and bag.
These features in the equipment have been developed to accommodate bending of the back and up and down and forward and backward movements of each hip and the hip-supported belt.
In addition, a sternum strap and adjustable stabilizer straps, connecting the pack bag with the hip belt and the shoulder harness, have been introduced to stabilize and limit the movement of the load, as required.
Stated otherwise, there has been a trend toward providing suspension systems for the pack bag which will better accommodate the movements of the hips and back of the user, while still maintaining the load in a desired, comfortable and stabilized position.
It is the object of the present invention to advance this trend by providing a novel suspension system which is characterized by a high order of capability for accommodating the various movements of the user.